This invention relates to hand saws and more particularly to the type commonly referred to as hack saws.
Known hack saws of the type considered here have a common design problem relating to bending moments transmitted to the saw blade when tension is applied to the ends of the blade and when the blade is loaded in the cutting mode. Recognition of this fundamental problem is illustrated by the multitude of solutions suggested by those skilled in the art.
Hack saws are traditionally, and almost universally, made having a longtitudinal frame member normally horizontal with vertical downward members at each end. The bottom extremities of the vertical members having means for fastening and applying tension to the saw blade between the two members. Most usually one of the vertical members serves as the saw handle, the other as a blade support arm.
There have been a number of hack saw designs which use a combination of tension and compression members in the frame assembly. The following U.S. Patents disclose such designs:
U.S. Pat. No. 2,796,098
U.S. Pat. No. 2,808,086
The primary objective of this invention is to provide a frame assembly relatively free from bending moments or distortion in the plane of the plane common to the horizontal members and the front and rear vertical members.